Animation rotation of an object around another boject's fixed vertices
Yes this is possible.
It helps to be aware of a couple of things.

You can rotate an object around one of the 3 main world axies, by pressing R and then either X, Y or Z.

You can rotate an object around one of its 3 internal axies, by pressing R and then either X, Y or Z twice. (if you tilted an object a bit the world axies and the internal axis no longer align)

In order to rotate your bay door object around the red highlighted edge, you have to place the origin (a pivot) somewhere on this edge and align this edge with one of the 6 aforementioned axis and then make this orientation it's normal state, so to say, by applying the rotation.


So select your door in the 3D viewport, rotate it in a way so the red edge is parallel to a world axis (the X-axis for instance). Then (also in the 3D viewport) go to Object &gt; Apply &gt; Rotation.
Lastly rotate and move it back into its place on the plane. Now if you press R and then X twice, the door should rotate around the red edge.